Unit 1 When is your birthday?-
thirteenth 13th fourteenth 14th fifteenth 15th sixteenth 16th
seventeenth 17th eighteenth 18th nineteenth 19th
twentieth 20th twenty-first 21st twenty-second 22nd
thirtieth 30th fortieth 40th fiftieth 50th sixtieth 60th
seventieth 70th eightieth 80th ninetieth 90th hundredth 100th
基數詞變序數詞口訣：
一二三，特殊記；-th從四加起。
八去t、九減e， ve要用f替。
ty結尾，y變為ie。
要是遇到“幾十幾”，只變個位就可以。
注意：
1. 序數詞前要加the，如果序數詞前有物主代詞或名詞所有格則不再用the。
sunday is the first day of a week.
my first teacher is miss li.
2. a/an 也能與序數詞連用，意為“再一”“又一”相當于another。
now they have a second child--a son.
a third man went into the room.
（三）語言運用：talk about dates and ages談論日期和年齡
when is your birthday?
how old are you?
1. which age groups in our culture like to talk about how old they are and which age groups don’t? in the united states, young children like to tell how old they are. teenagers are sometimes sensitive about age questions because they want people to think they are older than they really are. after age 25, it is not considered polite to ask someone’s age, except for business reasons. many people in the united states think it’s good to be young and bad to be old.
2. most american children celebrate birthdays with a cake with lighted candles on top, one candle for each year of their age. the birthday boy （or girl） is supposed to make a wish （without telling anyone what it is） and blow out the candles. if he blows out all of the candles with one breath, the wish will come true. singing "happy birthday to you" is also a tradition on birthdays.
some birthdays are more important than other birthdays, especially in the life of a teenager and young adult.
age 13: becomes a teenager
age 16: can obtain a driver’s license in the united states （for an automobile）
age 18: can register to vote
age 21: can legally drink alcohol
3. in china, people sometimes celebrate their lunar birthday rather than their solar birthday. chinese people also use twelve animals to symbolize the year in which one is born. the animals represent the twelve earthly branches, and they are the rat, the cattle, the tiger, the rabbit, the dragon, the snake, the horse, the sheep, the monkey, the rooster, the dog, and the pig.